The present invention relates to a cutting tool for cutting off and grooving by turning and an indexable insert (throwaway tip) for such a cutting tool.
Shown in FIG. 13 is a related indexable insert 101 for a bit or cutting tool used for cutting off or grooving by turning. The insert 101 has a pair of projections (beveled walls) 120, 120 on a rake face 116. The projections 120, 120 are disposed adjacent an end cutting edge 115 and the opposite ends of the rake face 116. With such an insert 101, a chip K is forcedly pressed against the projections 120, 120 and deformed into a convexly or V-like bent cross section before being removed from the place where cutting is performed.
The chip K deformed as above by such an insert 101 is higher in rigidity as compared with a chip of a flat cross section and can be easily divided into sections of suitable lengths even if it is removed so as to have a spiral shape. Thus, the chip does not coil around the cutting tool, work or chuck and therefore the insert 101 is advantageous in the disposal of chip.